The invention relates generally to space-based payload deployment systems and, more particularly but not by way of limitation, to a self-contained system for ejecting small to medium sized payloads from a space vehicle.
To deploy small to medium sized payloads from the Space Transport System""s Orbiter vehicle (the xe2x80x9cSpace Shuttlexe2x80x9d), the National Aeronautics and Space Administration (NASA) currently uses a design known as a Get Away Special (xe2x80x9cGASxe2x80x9d) carrier. The GAS carrier system provides mechanical and electrical support for an encapsulated payload. GAS carriers can accommodate payloads up to approximately 200 pounds in a volume of up to 5 cubic feet and are typically mounted to a Space Shuttle""s cargo bay side wall or to a cross cargo bay truss. For payloads that are to be deployed (ejected) during flight, GAS carriers are fitted with a motorized door. Prior to deployment, the door is opened and a launch mechanism within the carrier is activated to eject the payload.
Door mechanisms provide safety and operational failure potential that can impact a Space Shuttle""s on-orbit operations. For example, prior to deploying a payload the door must be opened. If the door fails to open, the deployment must be aborted. If the door opens, it must be closed prior to the Space Shuttle returning to earth. Should the door fail to close following deployment (or if the deployment fails for another cause), an astronaut may be required to egress the vehicle to manually close it. Such activities (known as a space-walk or Extra-Vehicular Activity, EVA) present their own risks and drive additional safety requirements for the payload and deployment system. One illustrative safety requirement is the need to eliminate xe2x80x9csharp edgesxe2x80x9d that may endanger an astronaut during an EVA.
Thus, it would be beneficial to provide a payload ejection means that has in inherently reduced risk of failure and, in the event of failure, manifests a safe return to earth environment by (for example, by not introducing potential sharp edges to astronauts engaged in extravehicular activities). This, and other benefits and advances are provided by a deployment system in accordance with the invention.
In one embodiment, the invention provides a system to deploy one or more payloads. The system includes an external tube having an open end, a payload container that fits within the external tube and having an end cap that, when in place, seals the external tube""s open end, and a separation means to separate or eject the payload container from the external tube. In another embodiment, the payload may be directly coupled to the end cap such that no additional payload container is needed. In either, or both of these embodiments, additional payload(s) may be coupled to an inner surface of the external tube distal from the end cap. If the additional payload(s) are fixedly attached to the external tube, they may be exposed to microgravity but not deployed. If the additional payload(s) are coupled to the external tube via a separation system, they may be deployed. Embodiments utilizing a payload container may encapsulate one or more payloads and may further be adapted to separate into two or more pieces to deploy each of the one or more payloads in a controlled manner subsequent to the payload container""s ejection from the external tube.